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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Latest News
Russia withdraws from 25-year-old weapons-grade plutonium agreement
Russia’s lower house of Parliament, the State Duma, approved a measure to withdraw from a 25-year-old agreement with the United States to cut back on the leftover plutonium from Cold War–era nuclear weapons.
George H. Miley, S. C. Hu, V. Varadarajan
Fusion Science and Technology | Volume 18 | Number 4 | December 1990 | Pages 633-640
Alpha Particles in Fusion Research | doi.org/10.13182/FST90-A29256
Articles are hosted by Taylor and Francis Online.
Alpha-particle ash accumulation in tokamaks and two possible ash control techniques are discussed. The effect of thermal alpha-particle ash accumulation on plasma performance is examined using a zero-dimensional analysis with profile corrections. Alpha-particle accumulation is shown to have serious effects on ignition requirements. An analytical model developed to predict the effect of sawtooth disruption on ash accumulation is discussed. The analytical results indicate that the sawtooth is effective when the temperature profile is parabolic or flatter. Alpha-particle ejection by a fishbone oscillation is envisaged to be helpful in ash control, and a model of the physics in a large-aspect-ratio approximation is discussed using an extended version of a Chen et al. formalism. The trapped particle destabilization of the internal kinks due to the alpha particles and a second hot-particle species is considered, and the expected oscillation frequency and growth rates are derived.